Hans Duffels's research while affiliated with Naturalis Biodiversity Center and other places

...       So far, Oncocephalus squalidus (Rossi, 1790) (Heteroptera: Reduviidae) has been reported for the islands of La Palma and Tenerife (HEISS & BÁEZ, 1990;RIBES & RIBES, 1997;AUKEMA et al., 2006AUKEMA et al., , 2013ROCA-CUSACHS et al., 2020). Now, the island of Lanzarote can be added to the list of the distribution of O. squalidus on the Canary Islands: On 20-08-2021, an adult specimen ( Fig. 1) was photographed in the courtyard of a private house in Costa Teguise, located at the eastern coast of the island (see here). ...

... However, the ''tuned resonator'' alone cannot account for the very high levels of acoustic energy radiated by the relatively small animal (MacNally and Young 1980), which are mainly attributed to non-linear characteristics of the signal (Hughes et al. 2009). Singing animals can adjust the resonant properties by stretching and raising the abdomen, thus enlarging the resonant cavity inside as well as the room between thorax and abdomen (Gogala et al. 2004; Boulard 2006 ). Adjustment of the thorax–abdomen gap may increase the sound volume by tuning the cavity to the eigenfrequency of the tymbal plate, while dilatation of the abdomen might raise the sharpness of tuning and reduce the damping (Pringle 1954; Bennet-Clark and Young 1998). ...